Purpose To investigate the influence of ametropia on stereopsis and its mechanism by using the disparity evoked potential testing. Methods A new set of static random dot stereograms was utilized as a stimulation to elicit the disparity evoked potentials in 21 ametropes and 40 stereo normal subjects. Rezults The P250 wave,which was related to stereoscopic stimulation in ametropes,was recorded in both the ametropes and emetropic stereo normal persons in this series,and the characteristic changes of P250 wave with increasing visual disparity in ametropes were similar to those in normal subjects.The differences of mean amplitudes and latencies of P250 waves between myopes and hyperopes were not significant. Conclusion Ametropia in full correction dose not significanly affect the function of stereopsis. (Chin J Ocul Fundus Dis,1998,14:225-227)
Objective To study the recovery and mechanism of nerve root under variable chronic injury and to determine the alerting index of the evoked potential of the irreversible injury to the nerve root, so as to offer the evidence for selecting treatment methods, judging prognosis and grasping treatment juncture.Methods Autogenous cancellous bones were planted into the right C7-8 and C8T1 intervertebral foramens in 30 cats with weight 3-5 kg to make chronicinjury models. The left side was for auto-contrast. By 24 weeks’ observation anddynamic supervisory of evoked potential, the injury degrees were ascertained and classified into Ⅰto Ⅴdegree groups. Then the operation of decompression was performed on every group. During the following 32 weeks, the evoked potential survey and pathological tissue examination were made every week to observe the function recovery of the injured roots.Results The tissue form and functionof the nerve roots with ⅠandⅡdegree injuries recovered well within 2 to 6 weeks. Those with Ⅲ degree injury began to recover in the 4th week, and graduallyrecovered to normal 12 weeks later. In the group of Ⅳ degree injury, the recoverywas slow. They could recover completely in 3 of 6 cats, partly in 2 and hardly recovered in 1. The function and tissue form of nerve roots with Ⅴdegree injury could hardly recovered. Conclusion In the case that the compression has been removed before the nerve roots suffer Ⅲ degree injury. The tissue form and function of the nerve roots will recovered satisfactorily, whereas they may suffer irreversibly injury by Ⅳdegree injury, and even can hardly recover by Ⅴdegree injury. During the supervisory process of the recovery of the injured nerve roots, sensitive evoked potential is a sensitive sign of early recovery and motion evoked potential is a reliable sign of recovery extent.
A new form of static random-dot stereograms free of monocular clues was designed as stimulus to elicit disparity evoked potentials in 40 normal subjects.A characteristic wide positive wave at about 250ms was consistently recorded in disparity stimulation,which may be regard as evdence of the presence of stereopsis.In constrast,recordings for monocular stimulus all demonstrated a relatively smaller and sharper positive wave with a markedly shortened latency. （Chin J Ocul Fundus Dis,1993,9:214-217）
purpose To study the visual electrophysiological changes in patients with chronic glomerulonephritis. Methods The visual evoked potentials(VEP) and electroretinogram(ERG) of 26 subjects with chronic glomerulonephritis in 51 eyes were recorded. Results Ours studies showed the patients with chronic glomerulonephritis had pathologic visual electrophysiologic abnormalities.The N 75 peak latency,b wave peak latency O 1 peak latency and total amplitude of OPs in chronic glomerulonephritis patients without fundus sign showed remarkable difference. Conclusion These changes suggested visual electrophysiological examination may be valuable in early diagnosis of retinal disfunction in patients with chronic glomerulonephritis. (Chin J Ocul Fundus Dis,1998,14:162-164)
This paper is an introduction about the resultsof SEP monitoring in 36 case from 179 cases ofperipheral nerve injuries which have been followedup at least 6 months,since the beging of 1985 tothe end of 1989 in Dapin Hospital. These cases were injured by nerve overstretching 5 cases, complicated with fracture in 14patients, sharp instrument cutting in 17 patients.Of them injured in brachial plexus 3 cases ,axil-lary nerve 1 case, median nerve combined with ul-nar nerve 3 cases, ulnar nerve 12 cases, sciatic nerve, posterior tibial nerve, common peroneal nerve and femoral nerve were 1 case. All the SEP examination results showed closely coordination with clinical entities. Therefore, SEP monitoring peripheral nerve injuries manifested very importent significance in judgement of the injured nerve function.